fix: support Qdrant backend on non-AVX CPUs

- doctor: skip LanceDB check when qdrant_storage/ dir detected
- topology: use daemon socket instead of local store (avoids lancedb crash)
- qdrant_store: add records_as_dataframe() + wire into _TableShim
  so build_runtime_graph() works with Qdrant (was returning empty)

src/iai_mcp/doctor.py

@@ -433,7 +433,31 @@ def check_f_lancedb_readable() -> CheckResult:
     Open a MemoryStore handle. The constructor opens the lancedb connection;
     if the directory is corrupt / permission-denied / disk-full, the
     constructor raises and we report FAIL.
+
+    Skips gracefully when Qdrant is the active backend or lancedb is
+    unavailable (non-AVX CPU, etc.) — returns PASS with skip reason.
     """
+    from iai_mcp.store import _use_qdrant
+
+    if _use_qdrant():
+        return CheckResult(
+            "(f) lancedb store readable",
+            True,
+            "skipped (Qdrant backend active)",
+        )
+
+    # Heuristic: qdrant_storage/ directory present → Qdrant is the active
+    # backend even if QDRANT_URL is not set in the current shell (e.g.
+    # systemd service provides it but interactive shell does not).
+    env_path = os.environ.get("IAI_MCP_STORE")
+    store_root = Path(env_path) if env_path else (Path.home() / ".iai-mcp")
+    if (store_root / "qdrant_storage").exists():
+        return CheckResult(
+            "(f) lancedb store readable",
+            True,
+            "skipped (Qdrant backend detected via qdrant_storage/)",
+        )
+
     try:
         from iai_mcp.store import MemoryStore
 
@@ -443,11 +467,24 @@ def check_f_lancedb_readable() -> CheckResult:
             True,
             "opens without error",
         )
+    except KeyboardInterrupt:
+        raise
+    except SystemExit:
+        raise
     except Exception as e:  # noqa: BLE001 — surface any open failure
+        # Non-AVX CPUs may crash in lancedb native libs (SIGILL); treat as
+        # unavailable rather than a store corruption failure.
+        exc_name = type(e).__name__
+        if exc_name == "IllegalInstruction" or "illegal" in str(e).lower():
+            return CheckResult(
+                "(f) lancedb store readable",
+                True,
+                f"skipped (lancedb unavailable on this CPU: {exc_name})",
+            )
         return CheckResult(
             "(f) lancedb store readable",
             False,
-            f"open failed: {type(e).__name__}: {e}",
+            f"open failed: {exc_name}: {e}",
         )